Five-decade international trends in the relation of perinatal mortality and congenital malformations: stillbirth and neonatal death compared.

The relation between long-term temporal trends in stillbirth and neonatal death rates and the congenital malformation frequencies in such deaths were analysed, using data from hospital-based European, USA, and Canadian reports published from 1950. In the last 50 years the overall perinatal mortality rate has fairly steadily improved, decreasing by 65-80%. This was accomplished by the control of some serious problems of early life. However, lingering disorders form an ever larger proportion of the causes of perinatal mortality. Among the prominent of these are congenital malformations, accounting for nearly 30% of perinatal deaths at present. However, this figure conceals important differences between stillbirths and early neonatal deaths. For example, although stillbirth and early neonatal mortality rates have decreased to similar extents during these years, congenital malformations, which were almost equally frequent causes of death in both of them at the beginning of this period, are now about twice as common in early neonatal (one week) deaths as in stillbirths. Other differences between them are in birthweight-related malformation frequencies and in characteristic arrays of malformations. The significance of these patterns and of some geographical variations, and the likelihood of continuing improvement in the stillbirth and early neonatal mortality rates are discussed.